<?php

namespace App\Http\Controllers;

use App\Libs\WeChatPublic;
use Redis;

/* 微信JSSDK */

class WeChatJSSDK {
    private $appId;
    private $appSecret;
    private $url;

    public function __construct() {
        if(!config('constant.wechat_have')){
            return 0;
        }
        $this->appId = config('constant.wechat_app_id');
        if(!$this->appId){
            return 0;
        }
        $this->appSecret = config('constant.wechat_app_secret');
        $this->url = request('url') ? request('url') : url()->full();
    }

    public function getSignPackage() {
        $jsapiTicket = $this->getJsApiTicket();

        // 注意 URL 一定要动态获取，不能 hardcode.
        // $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
        // $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
        $url = $this->url;

        $timestamp = time();
        $nonceStr = $this->createNonceStr();
        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

        $signature = sha1($string);

        $signPackage = array(
            "appId"     => $this->appId,
            "nonceStr"  => $nonceStr,
            "timestamp" => $timestamp,
            "signature" => $signature,
        );
        return $signPackage;
    }

    private function createNonceStr($length = 16) {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    private function getJsApiTicket() {
        $redis = Redis::connection('public');
        $seconds = 7000; //token缓存的时间，单位 秒，微信服务器2小时过期
        $ticket = $redis->get('wx_jsapi_ticket');
        // $redis->exists('wechat_access_token') === 0
        if ($ticket === null) {
            $wx = new WeChatPublic();
            $accessToken = $wx->getAccessToken();
            $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
            $res = json_decode($this->httpGet($url));
            $ticket = $res->ticket;
            $redis->set('wx_jsapi_ticket', $ticket, 'EX', $seconds);
        }
        return $ticket;
    }
    private function httpGet($url) {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_URL, $url);

        $res = curl_exec($curl);
        curl_close($curl);

        return $res;
    }
}
